Norton International
This 1932 Norton International shows the rigid frame and girder forks of the early machines.
Norton International Background & History
The Norton International was in production from 1931 through the 1957 model year. 27 years is a very long time in the motorcycle business. Produced in two displacements, the Model 40 with 350cc and the Model 30 with 500cc, both were Overhead Cam (OHC) engines that were designed for speed. Although many were street legal road bikes, they were often outfitted by the factory, to the specifications of the buyers, for road racing. The variety of parts and custom machine work that could be applied was impressive. During the Norton International’s heyday, the 1930s, it was fast enough, and competitive enough to win a major road events like the Isle of Man TT, often with 1-2-3 podium positions. Prewar racing greats like Jimmy Simpson, Stanley Woods and Jimmy Guthrie all rode and won on the Norton International.
This 1951 Norton International features the 'Garden Gate' frame with plunger rear suspension and Roadholder telescopic forks.
Prewar Norton International Features
Norton had garnered lots of experience building powerful singles. The Model 18, which launched in 1928 was one of the fastest bikes at the time and won many races. It was an OHV (Overhead Valve) design while the Norton International was OHC (Overhead Cam). The Model 18 even shared it's 79mm X 100mm bore and stroke with the International. Of course Norton built perhaps the ultimate 500cc single at the time, the Norton Manx which was actually a DOHC (Dual Overhead Cam) design. So, Norton was imminently well qualified to build another power single like the International. In fact, the bottom end was based on that of the Model 18. A new OHC top end top end was added with a vertical shaft running up the right side with bevel gears on each end to drive the cam. The tunnel that the bevel shaft ran through along with the removable timing cover on top sort of looked like a cricket bat, which cricket-loving Brits quickly picked up on. At the time of the Model 18's launch, Norton's advertising tag line was "Unapproachable". At the time, that was certainly true of the Model 18 and soon it applied to the International as well, and truly most of Norton's high performance bikes throughout their long and rich history. Nortons have always been fast.
Prewar Norton Internationals road on girder front forks and rigid frames, with a cast iron cylinder and head. Bore and stroke of the 500 models was 79mm X 100mm giving it an actual displacement of 490cc. The engine made 29.5 hp at 5500 rpm, but the bike was no lightweight at 380 lbs. The single-overhead cam (SOHC) engine featured exposed hairpin valve springs, designed to be quickly changed during a race. Quick-change rear wheels were another race-proven feature. Gearboxes changed a couple of times in the mid-30s and the engine gained an alloy cylinder barrel and cylinder head with bronze cylinder liner in 1936 as an option. In 1938 the rigid frame was ditched in favor of Norton’s new Garden Gate frame with rear plunger-type suspension and in 1938 the new Roadholder Telescopic Forks replaced the ancient girder front end. World War 2 ended all the fun until 1947 when civilian production resumed.
1951 Norton International.
Postwar Norton International Features
Postwar, the 1947 Norton International was fitted again with a cast iron barrel and head, but the all-alloy top end reappeared in 1950. Again, Norton custom fitted and tuned bikes to buyers’ specifications, and many bikes were unique. Of course racing machines didn’t have mufflers or lights. In 1951, the ancient Garden Gate frame was replaced with the state-of-the -art ‘Featherbed Frame’ and it completely transformed the bike, as it always did. However, as the 1950s progressed, other bikes in its class outperformed the Norton International. The BSA Gold Star and Norton’s own Manx could run circles around it. This and the increasing dominance of the vertical twin spelled the end in 1957, although Norton continued to produce them on a small scale for a limited number of buyers who special-ordered them. The 1957 and special-ordered 1958 Norton Internationals, only around 12 made, sported new styling with chrome side panels on the tank and full-width brake hubs, along with a new Lucan headlight and a new exhaust system.
1951 Norton International engine.
Norton International sets World Record
The Norton International has the distinction of holding a number of world speed records at the concrete bowl track in Montlhery, France in 1935. Rider Jimmy Guthrie set several records that day including the one-hour world speed record at 114.09 mph. He also broke the 50 km, 50 mi, 100 km and 100 mi records.
This 1956 Norton International has the Featherbed Frame.
Norton International Books
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